PoE Limits for GS105PE
The GS105PE switch is a great idea and potential problem solver. Unfortunately, due to one design flaw, it is only "almost" useful.
There are a few different switches that support PoE Passthrough on a single port. What makes this switch so awesome is that it has two ports. With an 802.3at (PoE+) feed, there is enough power to power two devices of common PoE types (for example, two PoE telephones). Of course, with this its also potentially possible to plug in two devices that use too much power and end up overloading the feed port. Fortunately, MOST poe devices out there do not have this problem.
Unfortunately, this switch is hamstrung by a design choice: the overload problem is solved by PoE class limitations rather than actual current limits. In order to use both ports, you have to plug in class 1/2 devices, if you have even one class0 or class3 device, then you only get one. Period. Even if that device only wants 2.5w.
This is a more extreme problem than it appears because most PoE PE chip makers have switched to only making class 3 chips. Thus most devices advertise class 3, even if they only need class 2. Except for this switch, this is no issue, as normal PoE switches regulate by combined power, not class. That's why I can get an 8 port 60W PoE switch that supports class 3. At full class 3, that allows nearly 13 watts per port, or 104W for all 8 ports.
It appears Netgear used this worst-case design method when designing this device. Please correct this huge oversight and just use power limiting rather than class-based limiting. It would be fine to shut off the port output and flash the power light if the total available budget is exceeded. Without that, this becomes a single-port PoE passthrough, not the two port its advertised as.
Palouse Technology Services
(who is now returning 3 of these devices just purchased, as they are useless as currently implemented)
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